package com.sqnu.dashe.controller;

import com.sqnu.dashe.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.UUID;

/**
 * @author mmy
 * @create 2023-06-09 16:36
 * @description
 */
@RestController
@Slf4j
@RequestMapping("/common")
public class CommonController {
    @Value("${dashe.path}")
    private String bassPath;
    /**
     * 文件上传
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){
        //file是一个临时文件，需要转存到指定位置，否则本次请求完成后会将临时文件删除
        log.info(file.toString());

        //获取原始文件名
        String originalFilename = file.getOriginalFilename();
        String substring = originalFilename.substring(originalFilename.lastIndexOf("."));
        //利用UUID重新生成文件名，防止文件名称重复造成文件覆盖
        String fileName = UUID.randomUUID().toString() + substring;
        //如果当前目录不存在，则创建一个目录
        File file1 = new File(bassPath);
        if (!file1.exists()) {
            file1.mkdir();
        }
        //把临时文件转存到其他位置
        try {
            file.transferTo(new File(bassPath+fileName));
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        return R.success(fileName);
    }

    /**
     * 文件下载
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response){
        try {
            //输入流
            FileInputStream fileInputStream = new FileInputStream(new File(bassPath + name));
            //输出流，将文件写回浏览器，在浏览器展示图片
            ServletOutputStream outputStream = response.getOutputStream();

            response.setContentType("image/jpeg");

            byte[] bytes = new byte[1024];
            int len = 0;
            while ((len = fileInputStream.read(bytes)) != -1) {
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }
            outputStream.close();
            fileInputStream.close();
        } catch (Exception e) {
            throw new RuntimeException(e);
        }

    }
}
